1. Field of the Invention
The present disclosure relates to a passive cooling system of a containment building to which a plate-type heat exchanger is applied and a nuclear power plant including the same.
2. Description of the Related Art
Reactors are divided into active reactors using active power such as a pump and passive reactors using passive power such as gravity force, gas pressure according to the configuration method of a safety system. Furthermore, reactors are divided into loop type reactors (for example, Korean pressurized water reactor) in which a main component (a steam generator, a pressurizer, a pump impeller, etc.) is installed at an outside of the reactor vessel and integrated type reactors (for example, SMART reactor) in which the main component is installed at an inside of the reactor vessel according to the installation location of the main component.
In the nuclear power plant industry, a passive containment building cooling system (or containment building cooling system) has been mostly used as a system for condensing steam and cooling internal atmosphere in order to maintain the integrity of the containment building when coolant or steam is discharged to increase a pressure within the containment building (or reactor building, containment vessel, safety guard vessel) due to the occurrence of a loss of coolant accident or steam line break accident in various reactors including an integrated type reactor.
For a method of being used with the purpose similar to that of the passive containment building cooling system, a method of using a suppression tank for guiding steam discharged to a containment building to the suppression tank (commercial BWR, CAREM: Argentina, IRIS: Westinghouse Company), a method of applying a steel containment to cool (spray, air) an external vessel (AP1000: Westinghouse), and a method of using a heat exchanger (SWR1000: France Framatome ANP, AHWR: India, SBWR: GE), and the like are used. For a heat exchanger of the containment building cooling system, a shell and tube type heat exchanger or condenser (SBWR: U.S. GE Company) is mostly applied thereto. In general, a containment structure for protecting an outside of the reactor vessel (or reactor coolant system of a loop type reactor) is referred to as a containment building (or reactor building) when fabricated and constructed using reinforced concrete, and referred to as a containment vessel (safety guard vessel in case of a small size) when fabricated and constructed using steel.
The performance of a heat exchanger in a containment building cooling system mainly depends on a condensation phenomenon of steam. When atmosphere is not efficiently circulated, steam may not be efficiently supplied thereto, thereby reducing the performance of the heat exchanger. Furthermore, a lot of devices and structures may be disposed within a containment building in a nuclear power plant in which a containment building cooling heat exchanger is disposed within a containment building, and thus there is a difficulty in the layout, and thus reduction in size and weight is required.